Method of deodorizing and pasteurizing liquids



April 26, 1938. RQGERS 2,115,470

METHOD OF DEODORIZING AND PASTEURIZING LIQUIDS Filed July 2, 1954 2Sheets-Sheet 1 4 INVENTOR. C'Z'a r185 P056213 ATTORNEY.

April 26, 1938. c. E. ROGERS 2,115,470

METHOD OF DEODORIZING AND PASTEURIZING LIQUIDS Filed July 2, 1934 2Sheets-Sheet 2 INVENTOR. Cfiarles Z5. Rogers.

A TTORNE Y.

not higher than 185 degrees Fahrenheit which is Fig. '3 is a sectionalelevation of a portion of a- 10 does not eliminate'the spores and thisinvention form of vacuum chamber utilized in the cooling 15 milk andcream to practically 300 degrees F. with-- ing it rce of supplythroughan inlet 2 and 40 it may be uniformly heated throughout its mass conduit1 and has an inlet 8 connected with a Patented Apr.2 6,19 38 I j z 5-470' UNITED- STATES PATENT, OFFICE METHOD OF DEO-DORIZING 'AND PASTEUR-IZING LIQUIDS Charles E. Rogers, Novi, Mich. Application July 2, 1934,Serial No. 733,434 '1 Claims. (01. 99-431) This invention relates to amethod for treating These and other objects and various novel fea milkand cream to render the same practically tures of the invention andapparatus for pernon-sporiparous and may be employed in treatforming theprocess are hereinafter more fully ment of other liquids containingbacteria pracdescribedand claimed, and the preferred form '5 ticallywithout change in the method of treatof apparatus embodying my inventionis shown 5 ment. in the accompanying drawings in which Heretofore, milkand cream have been subject- Fig. 1 is a plan view of the apparatuspartially ed to what is known as the pasteurizing process in section. inwhich the liquid is heated to a temperature Fig. 2 is an end elevationthereof.

understood by the trade to be practically the convenient form of heatingdevice.

highest temperature to which milk and cream Fig. 4 is a cross sectionthereof taken on line may be subjected without detrimental chemical 1-4of Fig. 3. or physical change. Such treatment, however, Fig. 5 is asectional elevation of a convenient seeks to provide a process andapparatus for perof the treated milk.

forming the same by which the milk or cream Fig. 6 is a cross sectiontaken on line 6-6 of may be subjected to a temperature of practicallyFig, 5. A 300 degrees F. without injury in odor or flavor Fig. 7 is asection taken on line 1- of Fig.1

or detrimental chemical change and not only are showing the steamcontrol valve. 20

the spores practically eliminated but the deleteri- Fi 8 i longitudinalsection of a different ous odors and flavors with which milk is oftenform of heater tube. contaminated are also eliminated. Thus the milk Theessential characteristic of this invention or cream that hasdeteriorated through developresides in the means for quickly heating themilk -35 ment of bacteria and the freshness and flavor uniformlythroughout its mass to a high degree p d y deleterious Volatile mattermay. by and practically instantaneously discharging the the processherein described, be eliminated and a heat therefrom or at leastsufficiently rapidly as product secured that has theodor and flavor of ato prevent a detrimental physical or chemical fresh milk or cream whichwill be retained for a change in the fluid due to the heating to so high3 materially greater period than is the case with a degree. One form ofheating device for quick pasteurized milk or cream. heating of theliquid is shown principally in Figs.

The object of the invention therefore is to pro- 1, 2 and 3 but otherforms may be utilized. vide a p cess and app us wherein the milk Theform of heater shown operates to inject and Cream y be raised to atemperature psteam into a comparatively thin film of liquid p mat ly 00d r es F- w t u production under treatment, it. being understood that byof detrimental odor, taste or deleterious physi-I liquid is meant any ofth known liquids Cal 1' Chemical c a d by practically quiring suchtreatment to eliminate the bacteria freeing the milk of bacteriaproducing spores. and spores. t

I have discovered that it is possible to heat The apparatus shownconsists of apum t out detriment providing the heating andsubsedischarging th same through a pipe 3 into a quent cooling aresufficiently ap that e cylinder 4. The pipe3 is connected to a header tOf heating to above a pasteurizing 5 on the cylinder 4 and to thisheader is connecture and cooling to sa d t p atur is p m d ed a heatertube 6 extending through the header in the neighborhood of "threeseconds of time. and into t cylinder 4 part way of its length 15 Thefeature of the invention resides not only The liquid discharged throughthe pipe 3 into the in t method whereby milk nd cream may be, headerlies in a thin film circumferentially of heated to SO high a degree butconsists further the tube G'Within the'header 5 and cylinder 4. in theapparatus for heating the .liquid wherein The heater tube 6 is connectedto a steam supply to the high temperature and in association with sourceof supply. A valve 9 may be positioned which is provided a means forpractically inin the conduit 1 adjacent the inlet and there isstantaneously discharging the heat from the fluid also in the conduit 1a valve Ill and in the chamwhich may thereafter be cooled to any desiredbered' member II is a temperature actuated dedegree. vice, a convenientform of which is shown in Fig. 55

7. This is a common known form of temperature control valve in which abellows member II] is mounted in a chambered member I I which byexpansion tends to close the valve H] in the valve housing Ill formingpart of the conduit I. There is a spring Ill tending to contract thebellows member and open the valve and on the upper end of the chamber His a temperature gauge I2. The conduit 1 connects directly to the memberI0 and is continued on the opposite side to connect with the heaterconduit 6 and there is also a valve controlled by-pass conduit l3connected with the inlet and passing around the temperature controlledvalve in and connected with the portion of the conduit 1 connected tothe heater conduit 6, it being desirable, as for instance in a cleaningoperation, to inject live steam directly into the tube 4 and about theassociated parts.

The heater conduit, particularly the portion extending into the tube 4,is provided with a series of circumferential grooves M in the bottoms ofwhich apertures l5 are provided leading to the interior of the tube 6and so inclined to the axis of the tube as to direct the steam forwardlyin the direction of the arrow in the tube 4. The milk or other fluidbeing treated passes in the space l6 between the wall of the heater tube6 and cylinder 4 and thus is in a thin film and is penetrated by thesteam jets issuing from the apertures l5 during the period of itspassing from the receiving end of the tube 4 to the end of the tube 6.Thus, due to the fluid being in a comparatively thin film and of itsbeing passed rapidly by the pump through this space, the fluid ispractically uniformly heated to the steam temperatur by the time itpasses the end of the tube 6. The length of this tube 4 to the header 11should be such that, with milk or cream at least, not more than twoseconds of time should elapse but this may be varied slightly withoutinjury to the milk due to the instantaneous cooling thereof hereinafterdescribed. The header H has a plate ill at its outer face to a recess ofwhich the tube l9 opens which tube connects to the diaphragm orexpansion device in the chamber H. A gauge, indicated at 20, is providedto enable the operator to read the temperature of the fluid at thispoint while the gauge l2 enables the operator to determine thetemperature to which the apparatus for operating the valve I0 issubjected.

The tube l9 and bellows member Ill to which it opens are practicallyfilled with a volatile fluid highly responsive t variations intemperature and the structure shown in Fig. 7 is so set as to maintainthe temperature of the liquid being treated practically constant. Whenthe temperature is maintained at about 300 degrees F. for a short periodboth the bacteria and spores are destroyed. If milk or cream is beingtreated the period should not exceed three seconds of time. The headeralso has connected therewith a discharge conduit 2| on which is a valve22 and a conduit 23 leads from the tube 2| to and discharges into avacuum chamber 24. which is shown diagrammatically in Figs. 1 and 2 andshown more in detail in Figs. 5 and 6. To maintain a temperature of 300degrees in the heater tube by means of steam, the steam, as is wellknown, must have a pressure of about 100 pounds per square inch. Thevalve 22 between the heater tube 4 and the tube 23 leading to the vacuum.chamber is adjustable by means of the hand wheel 22. The temperature ofthe fluid in the tube 4 is indicated by the gauge and if the temperatureis too low the valve must be closed slightly to bring up the pressure inthe tube 4 in order that the desired temperature may be attained. As theliquid passes the valve 22 to the conduit 23, the pressure must drop dueto the tube freely discharging to the vacuum chamber 24. The apparatusis thus controllable to maintain pressures and temperatures in the tube4 and the drop in pressure between the tubes 4 and 23 tends to collapseand crack the spores which are still subject to the heat of the liquidbefore the heat is discharged therefrom in the vacuum chamber. Thisvacuum chamber is preferably provided with a V shaped trough 25 adjacentits bottom into which an extension 26 of the tube 23 is positioned. Thistube 26 has a series of small apertures or slots therein to permit thefluid to pass freely from the tube 26 and as this fluid overflows theupper edge of the trough 25 it drops to the bottom of the vacuum chamber24 and may be instantly drawn oil through a discharge conduit 21. Withmilk or cream the liquid should be withdrawn quickly from influence ofthe vacuum as the casein and curd content tend to harden if the liquidremains in the chamber. Therefore the liquid should be constantlywithdrawn therefrom as rapidly as it is discharged thereinto so no greatamount of liquid is in the chamber at any time. The vacuum chamber is ofa type in which there is a trough 28 extending across the same above thetrough 25 and near the top of the chamber and at its end the tube 29 isprovided exteriorly of the chamber which is to be understood as beingconnected with the vacuum pump.

A spray of water may be discharged into the trough 28 by means of a pipe30 having a series of apertures therein and connected with a source ofsupply by a tube 3|. This spray falls into the trough 28 and vaporsrising in the vacuum chamber from the fluid discharged thereintopassthrough the spray to enter the trough 28 and thus the gases are drawnoff from the chamber by the vacuum pump which maintains about atwenty-five inch vacuum in the chamber 2 3.

Introduction of the highly heated fluid under pressure into the vacuumchamber under influence of the vacuum causes the same to practicallyexplode and to give up its heat and to free the fluid of the deleteriousodors and flavors and this cooling is practically instantaneous fromapproximately 300 degrees temperature of the fluid to the boilingtemperature of the chamber which is ordinarily about 130 degrees and asthe fluid is discharged from the vacuum chamber to the conduit 2! it maypass through a device for cooling the same materially below thetemperature of the vacuum chamber.

The heater here shown injects steam directly into the body of milk,cream or other material being treated. This is not material in'the caseof milk or cream wherein the cream is to be used in the making of butteror where the milk is to be In either form or the heater, however, theessential characteristic is in the rapidity with which 'themilk israised from pasteurizing temperature to 300 degrees F. and dropped topasteurizlng temperature or below. The movement of the milk or creamwhen in contact with the heater by the volume of fluid to be heated perunit of time and its speed of movement relative to the heating element.Thus it will be observed in recapitulation that by raising the fluidvery quickly to-a high degree of temperature and then discharging into avacuum chamber of a suificiently high degree of vacuum, the heat ispractically instantly discharged from the body of fluid and in thetreatment of any fluid, particularly milk and cream, this period ofheating should not exceed approximately four seconds of time from the.point of heating at high heat to the point of entering the vacuumchamber. Thus the p fi must operate and the conduits 4, 2i and I shouldbe of such length in comparison to the capacity of the pump as to causethe fluid to traverse the tube to the vacuum chamber before adetrimental physical orchemical change takes place in the fluid. Underthe conditions stated, the milk or cream being'treated will flow fromthe vacuum chamber sb nearly free from spores as to be practicallysterile. I

, From the foregoing description it is believed evident that variousobjects of the invention are attained by the apparatus describedincluding the method of treatment of the liquid, and. it is to beunderstood that various changes may be made in the apparatus and'thatthe temperatures to which the liquid is subjected may be varied somewhatfrom the specific temperatures mentioned, depending somewhat upon thecharacter of liquid being treated, without departing from the spirit andscope of the invention as set forth in the appended claims.

Having thus briefly described my improved method and apparatus fortreating liquids containing bacteria and spores, what I claim and desireto secure by Letters Patent of the United States is a 1. The method ofpasteurizing and deodorizing liquids which consists in causing theliquid to flow from a source of supply to a vacuum chamber in a confinedstream, submitting the liquid in a portion oithe stream to steam at atemperature of approximately 300degrees F. for a short period, thenabruptly reducing the pressure and continuing ,the liquid in asucceeding portion of the stream under its internal heat, dischargingthe liquid into a vacuum chamber wherein it is practically instantlyreduced to below atmospheric pressure and broken up into a fog likemist, and finally separately removing the vapor and the liquid from thechamber.

2. The method of pasteurizing and deodorizing lacteai fluids whichconsists in causing the liquid to flow from a source of supply to-avacuum chamber in a conflned stream, submitting" the liquid in a portionof the stream to direct con-.

tact with steam under pressure whereby the temperature is increased toapproximately 300 degrees F., for a short period and then, priorto'detrimental effect from the heat, practically instantaneouslyreducing the pressure and con,-

tinuing the liquid in a succeeding portion or the stream under itsinternal heat, then discharging the liquid into the vacuum chamberwherein it is practically instantaneously reduced to below atmosphericpressure and broken up into a fog-. like mist and separately removingthe vapor and the liquid from the vacuum chamber. 3. The method ofpasteurizing and deodorizin liquids containing bacteria and spores whichconsists in causing the liquid to flow from a source of supply to avacuum chamber in a confined stream, applying heat and pressure to theliquid in one portion oi. the stream to suddenly raise the temperature.thereof to approximately 300 degrees F., then reducing pressure andpermitting the liquid to continue to flow in a second portion of thestream under its internal heat, discharg ing the liquid from the saidsecond section through an orifice to the vacuum chamber to reduce thepressure to below atmospheric pressure, thereby causing the liquid toenter the chamber in the form of a fog-like mist under influence ofvacuum whereby the heat and volatile matter are removed and the liquidcooled to a temperature below that productive of detrimental eflect, andseparately removing the liquid 'andvolatile matter.

4. The method of pasteurizing and deodorizing liquids containingbacteria and spores which consists in causing the liquid to flow from asource of supply to a vacuum chamber in a confined stream, applying heatand pressure to the liquid in one portion or. the stream to suddenlyraise the temperature thereof to approximately 300 degrees F., thenreducing the pressure and permitting the liquid to continue to flow'in asecond portion of the stream under its internal heat, discharging theliquid from said second section into the vacuum chamber wherein theliquid as it enters the chamber is instantly reduced to belowatmospheric pressure and the liquid broken up into a fog-like mistsubject to influence of the vacuum whereby, the flavors, volatile matterand heat may be removed and the clarified particles may accumulate inliquid form and removing the liquid from the vacuum chamber separatelyfrom'the vapors and volatile matter.

5. The method of deodorizing and pasteurizing lacteal fluids whichconsists in first practically instantaneously raising the temperaturethereof. to approximately 309 degrees F,, then practicallyinstantaneously reducing the pressure, then discharging the same into avacuum chamber to practically instantaneously extract the heat wherebythe liquid is broken up into flnely divided mist like form underinfluence of the vacuum, and

separately withdrawing the vapors and liquids,

same to a vacuum chamber wherein, due to the degree of exhaust, theliquid is'instantaneously broken up into a flne mist and reduced intemperature to materially below that detrimental to the fluid, andseparately removing the vapors and the liquid. from the vacuum chamber.

'7. The method of deodorizing and pasteurizing lacteal fluids whichconsists in first practically instantaneously raising the temperaturethereof to approximately 300 degrees byv the injection of steam into athin flowing body of liquid maintained under pressure, then continuingthe stream in a conduit opening to a vacuum chamber whereby the pressureis reduced in the said conduit and the liquid flows in the conduit underits internal heat, discharging the fluid from the'con- CHARLES E.ROGERS.

